Note: Descriptions are shown in the official language in which they were submitted.
TITLE OF THE INVENTION
CONTROL LEVER ASSEMBL~
IN A SELF PROPELLED LAWN MOWER
BACKGROUND OF THE INVENTTON
1. Field of the invention:
The present invention relates to a control lever
assembly in a self-propelled lawn mower, and more
particularly to such a control level assembly having a
first control lever for controlling a clutch for
disconnectably transmitting power to driving wheels of the
self-propelled lawn mower, and a second control lever for
controlling another clutch for disconnectably transmitting
power to a grass-cutting blade.
2. Description of the Prior Art:
One known type of self-propelled rotary lawn mower,
as disclosed in Japanese Utility Model Laid-Open
Publication No. 54-115363, has a first control lever
mounted on a handle for connecting and disconnecting a
first clutch for driving wheels of the lawn mower, and a
second control lever mounted on the handle in juxtaposed
relation to the first control lever for connecting and
disconnecting a second clutch for controlling the operation
of a grass-cutting blade. In operation, the first control
lever is actuated in a direction to connect the firs~
clutch until it engages a projection on the second control
lever. Then, the continued movement of the first control
lever causes the second control lever to be actuated in a
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direction to connect the second clutch. Therefore, the
grass-cutting blade is rotated while the lawn mower is
moving along simply by operating the first control lever
only. The prior lawn mower is however diadvantageous in
5 that the second control lever is necessarily actuated at
all times when the first control lever is operated upon.
When it is desired to move the lawn mower for dumping
off the cut grass or simply toward another location
requiring grass cutting, it is not necessary to rotate
10 the blade and the second and hence first control levers
should be brought into the inoperative position. Conse-
quently, the lawn mower must be manually moved around as
the first clutch remains disconnected.
The present invention has been made in an effort to
15 overcome the foregoing prior problem.
SUMMARY OF THE INVENTION
A control lever assembly in a self-propelled lawn
mower including a prime mover, at least one wheel drivable
by said prime mover, a blade drivable by said prime mover
20 for cutting grass, a first clutch operatively coupled
between said prime mover and said wheel, and a second clutch
operatively coupled between said prime mover and said blade,
said control lever assembly comprising: (a) a first control
lever for selectively connecting and disconnecting said
first clutch; (b) a second control lever for selectively
connecting and disconnecting said second clutch; (c) an
engagement element mounted on said second control lever
-2-
and engageable with said first control lever to cause said
second control lever to be moved in a direction to con-
nect said second clutch when said first control lever is
moved in a direction to connect said first clutch; and (d)
means for moving said engagement element between an opera-
tive position in which said engagement element is engage-
able with said first control lever and an inoperative
position in which said engagement element is held out of
engagement with said first control lever, said means com-
prising a knob integrally formed with said engagementelement for moving said engagement element between said
operative and inoperative positions and including a mechanism
connected to said knob for locking said second control lever
in a position to disconnect said second clutch.
A control lever assembly in a self-propelled lawn
mower including a prime mover, at least one wheel drivable
by said prime mover, a blade drivable by said prime mover
for cutting grass, a first clutch operatively coupled
between said prime mover and said wheel, and a second clutch
operatively coupled between said prime mover and said blade,
said control lever assembly comprising: (a) a first control
lever for selectively connecting and disconnecting said
first clutch; (b) a second control lever for selectively
connecting and disconnecting said second clutch, (c) an
engagement element mounted on said second control lever
and engageable with said first control lever to cause
said second control lever to be moved in a direction to
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connect said second clutch when said first control lever
is moved in a direction to connect said first clutch; and
(d) means for moving said engagement element between an
operative position in which said engagement element is
engageable with said first control lever and an inoperable
position in which said engagement lever is held out of
engagement with said first control lever wherein said
means comprises a cam pivotally mounted on one end of
second control lever, a rod connected to one end of said
cam and extending longi-tudinally along said second
control lever, said engagement element being mounted on
an opposite end of said rod, and a cam guide surface
responsive to movement of said second control lever for
interfering with and angularly moving said cam to move
said engagement element into said operative position.
Accordingly, it is an object of an aspect of the
present invention to provide a control lever assembly in
a self-propelled lawn mower, capable of moving the lawn
mower while keeping a grass-cutting blade deactivated
against rotation.
An object of an aspect of the present invention
is to provide a control lever assembly in a self-propelled
lawn mower, which allows simple and easy switching
operation of a lawn mower control lever and a grass-
cutting blade control lever between engageable andrelease positions.
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The above and other objects, features and advan-
tages of the present invention will become more apparent
from the following description when taken in conjuntion
with the accompanying drawings in which preferred embodi-
ments of the present invention are shown by way of illus-
trative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly broken away of a
self-propeller lawn mower incorporating a control lever
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assembly according to a first embodiment of the present
invention;
FIG. 2 is a side elevational view of the control
lever assembly shown in FIG. l;
FIG. 3 is an enlaryed cross-sectional view taken
along line 3 - 3 of FIG. 2;
FIG. 4 is a fragmentary side elevational view, with
parts in cross section, of a housing portion of the lawn
mower in which a clutch for moving the lawn mower is
disposed;
FIG. 5 is an enlarged cross-sectional view taken
along line 5 - 5 of FIG. 4;
FIG. 6 is a plan view, partly in cross section, of a
clutch for driving a grass-cutting blade in the lawn mower;
FIG. 7 is a cross-sectional view taken along line 7 -
7 of FIG. 6;
FIG. 8 is a cross-sectional view taken along line 8 -
8 of FIG. 6;
FIG. 9 is a a side elevational view of a control
lever assembly according to a second embodiment of the
present invention;
FIG. 10 is a rear elevational view of the control
lever assembly as seen in the direction of the arrow A in
FIG. 9;
FIG. 11 is an exploded perspective view of components
of the control lever assembly of FIG. 9; and
FIGS. 12 and 13 are views similar to FIGS. 9 and 10,
-- 4
respectively, showing the position in which a control lever
for moving the lawn mower and a control lever for driving
the grass-cutting blade are simultaneously actuated in
mutual engagement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a self-propelled rotary lawn
mower has a housing 1 equipped with front and rear pairs of
wheels 2 vertically adjustably mounted respectively by
swingable arms 2b having levers 2a on the housing 1. the
housing 1 accommodates a rotary blade 3 for cutting grass
therein. An engine 4 is disposed on an upper surface of
the housing 1. The engine 4 is operatively connected to
the rear wheels 2 through a propeller shaft 5 (FIG. 4) and
a speed reducer 7 having a first clutch 6, and also
connected to the blade 3 through a second clutch 8
positioned directly below the engine 4. The lawn mower
also has a handle 9 extending rearward from the housing 1
and supporting on its end remote from the housing 1 a first
control lever 10 for connecting and disconnecting the first
clutch 6 and a second control lever 11 ajacent to the first
control lever 10 for connecting and disconnecting the
second clutch 8.
The first clutch 6 for moving the lawn mower
comprises a known dog clutch having, as illustrated in
FIGS. 4 and 5, a fork member 6b held in engagement with a
slider 6a and attached to a fork spindle 6c. When the
first control lever 10 is turned forward to a
3L2~
clutch-connecting position, the spindle 6c is angularly
moved by a wire lOa coupled to the first control lever 10
to connect the clutch 6 for thereby transmitting power from
the engine 4 to the rear wheels 2.
As shown in FIGS. 6 through 8, the second clutch 8
for driving the blade 3 is composed of a clutch plate 8a
connected to the blade 3, a drive flange 8b disposed above
the clutch plate 8a and coupled to the engine 4, a presser
plate 8c enagageable with the clutch plate 8a for
vertically moving the latter, and a cam plate 8d located
upwardly of the presser plate 8c. The cam plate 8d has cam
grooves 8f receiving therein balls 8e interposed between
the presser plate 8c and the cam plate 8d and having
varying depths along the circumferential direction of the
cam plate 8d. When the second control lever 11 is turned
forward to a clutch-connecting position, the cam plate 8d
is angularly moved about its own axis by a wire lla joined
to the second control lever 11 against the bias of return
springs 8g until the deeper portions of the cam grooves 8f
are positioned over the balls 8e, respectively. The balls
ae and hence the presser plate 8c are moved upwardly,
allowing the clutch plate 8a to be brought into frictional
engagement with the drive flange 8b under the resiliency of
a clutch spring 8h. The clutch 8 is now connected to
transmit power from the engine 4 to the blade 3.
As the first control lever 10 is moved to the clutch-
connecting position, it engages the second control lever 11
-- 6 --
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to move the latter therewith to the clutch-connecting
position. According to a first embodiment, as shown in
FIGS. 1 through 3, the second control lever 11 has an
engagement portion 12 with which the first control lever 10
is engageable, and the engagement portion 12 is movable
between a lower operative position in which it engages the
first control lever 10 and an upper inoperative position in
which it is held out of engagement with the first control
lever 10. More specifically, as illustrated in FIGS. 2 and
3, th~ engagement portion 12 projects integrally from a
knob 15 which actuates a locking member 14 into engagement
with a lever attachment bracket 13 to lock the second
control lever 11 in a clutch-disconnecting position. The
knob 15 is movably mounted in a grip 16 at the upper end of
the second control lever 15. When the knob 15 is pushed,
it remains pushed in a lower unlocking position to keep the
locking member 14 unlocked from the bracket 13. When the
knob 15 is pushed again, is returns to an upper locking
position to lock the locking member 14 on the bracket 13.
In the upper locking position of the knob 15, the
engagement portion 12 is retracted into the grip 16 in the
upper inoperative position. In the lower unlocking
position, however, the engagement portion 12 projects into
the lower operative position located in the path of angular
movment of an abutment 17 projecting from the first control
lever 3 as shown in FIG. 3.
As illustrated in FIG. 2, the first control lever 10
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has a stop 18 for engaging the locking member 14 to prevent
the same from being unlocked from the bracket 13 when the
first control lever 10 is turned to the clutch-connecting
position. ~s shown in FIG. 1, the handle 9 supports
thereon a throttle lever 19 for controlling operation of
the engine 4.
Operation of the self-propelled ro-tary lawn mower
thus constructed is as follows: The engine 4 is started,
and the knob 15 is pushed into the lower unlocking
position. When the first control lever 10 is moved to the
clutch-connecting position, the abutment 17 on the first
control lever 10 engages the engagement portion 12
projecting from the second control lever 11. Continued
forward movement of the first control lever 10 brings the
first and second control levers 10, 11 to the clutch-
connecting position. The first and second clutches 3, 8
are connected to cause the lawn mower to move along and the
blade 3 to rotate.
Conversely, when the knob 15 remains in the upper
locking position and the first control lever 10 is turned
to the clutch-connecting position, the second control lever
11 is kept in the clutch-disconnecting position since the
engagement portion 12 is in the inoperative position. Only
the first control lever 10 is therefore moved into the
clutch-connecting position. In this mode of operation, the
lawn mower is propelled whlle the blade 3 is prevented from
rotation.
-- 8 --
It is also possible to rotate the blade 3 while the
lawn mower is held at rest by moving only the second
control lever 11 to the clutch connecting position.
FIGS. 9 through 13 show a control lever assembly
according to a second embodiment of the present invention.
With the control lever assembly of the first embodiment,
the first and second control levers 10, 11 are brought into
mutually engageable relation only when the knob 15, or a
third member, is actuated in a direction different from
that in which the first and second control levers 10, 11
are movable. According to the second embodiment, however,
no such third member is required.
As shown in FIGS. 9 and 10, a lever attachment
bracket 21 having a bottom wall 21a is fixed to a lawn
mower handle 20, the bracket 21 having a channel-shaped
cross section. A shaft 22 is mounted on and extends
transversely through the bracket 21. On the shaft 22,
there are angularly movably mounted a first control lever
23 for connecting and disconnecting a clutch for moving a
lawn mower and a second control lever 24 for connecting and
disconnecting a clutch for driving a grass-cutting blade.
The first and second control levers 23, 24 are angularly
movable independently of each other. The first control
lever 23 is normally biased by a return spring (not shown)
to turn clockwise (FIG. 9) and the second control lever 24
is normally biased by a return spring 25 to turn clockwise.
A cam 27 is pivotally attached by a pin 26 to one end of
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the second control lever 24 adjacent to the shaft 22. The
cam 27 is normally biased to turn counterclockwise (FIG. 9)
by a spring 28 acting between an end of the cam 27 and the
shat 22.
As shown in greater detail in FIG. 11 9 a rod 27 has a
lower end attached to the end of the cam 27 and extends
along the reverse side of the second control lever 24 (see
FIGS. 9 and 10), with a shutter 30 fixed to the upper end
of the rod 27. The shutter 30 is in an upper position out
of interference with the angular movement with the first
control lever 23 when the first and second control levers
23, 24 are in a rear clutch-disconnecting position as shown
in FIGS. 9 and 10. Under this condition, the first
control lever 23 can be turned forward alone to a clutch-
connecting position to move the lawn mower while stopping
the blade against rotation. Or alternately, the second
control lever 24 can be turned forward alone to clutch-
connecting position to rotate the blade while lawn mower is
kept at rest.
The mode of operation in which the lawn mower is
moved along and at the same time the blade is rotated will
be described with reference to FIGS. 12 and 13.
The second control lever 24 is turned slightly
forward about the shaft 22 from the position shown in FIG.
9. The pin 26 with the cam 27 pivotally mounted thereon is
also turned about the shaft 22 until a distal end 27a of
the cam 27 rides onto an upper surface of the wall 21a of
-- 10 --
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the bracket 21. At this time, the cam 27 turnes clockwise
about the pin 26 while tensioning the spring 28. The
turning movement of the cam 27 lowers the rod 29 to move
the shutter 30 secured thereto downwardly into partially
overlapping relation to the first control lever 23 as shown
in FIG. 13.
The first control lever 23 is now turned forward
about the shaft 22. The shutter 30 is engaged by the first
control lever 23, and then the second and first control
levers 24, 23 are turned forward in unison to the clutch-
connecting position. Therefore, the lawn mower is moved
along and simultaneously the blade is rotated to cut grass.
The control lever assembly according to the second
embodiment enables the first and second control levers 23,
24 only to control the movement of the lawn mower and the
rotation of the blade highly efficiently.
The control lever assembly according to the present
invention can be incorporated not only in lawn mowers but
also in other self-propelled machines such as cultivators,
for example.
Although certain preferred embodiments have been
shown and described, it should be understood that many
changes and modifications may be made therein without
departing from the scope of the appended claims.
